Using the wet chemistry method, the surface of poly(aryl ether ether ketone) (PEEK) him aas selectively modified to produce PEEE-OH, PEEE-COOH, PEEK-glutamine, PEEK-NH2 and PEEK-SO3H samples displaying, respectively hydroxyl, carboxyl, amino acid, amine and sulphonyl functions. All the samples were analysed by XPS and time-of-flight (ToF) SIMS; the experimental data provided by both techniques were in good agreement, and allowed the chemical nature and the yield of the functional groups introduced by the different surface derivatizations to be determined. Copyright (C) 1999 John Wiley & Sons, Ltd.